Dyeing and dyes; these two words are related to one another. Without dyes, it’s not possible to dye materials. So dye is the main thinking of dyeing. But most of the time we do something wrong for what we face a lot of problems during dyeing. For this reason, we should know about the dyes, which we use in our dyeing process.
Dyes are coloring materials used in dyeing textiles materials. Besides, it can be defined as a substance that may be natural or synthetic used to change or add color to textile materials. Applying dyes to materials depends on the type of materials. Different materials have different chemical structures and different dyes have different chemical structures, so we have to know which dye is suitable for which materials.
Classification of Dyes:
There are different dyes such as readymade dyes, natural dyes, synthetic dyes, food dyes are available for the textile coloration process. The following are the types of dyes for wet processing technology. They are-
Ready-made dyes are water-soluble, water-insoluble, and ingrain in types. They are-
- Azoic Colors
- Oxidation Colors
- Mineral Colors
Natural dyes are the dyes that are produced naturally from different plant sources like roots, leaves, bark, berries, fungi, wood, lichens, etc. At the very beginning of dyeing history, the man started dyeing their materials with natural dyes. Indigo, woad, saffron, and madder are plant-based dyes which is much popular in Asia.
Synthetic dyes occupied the mark of dyes. Now a day most of the dyeing operation is done with synthetic dyes. The different factor is responsible for it. Synthetic dye is made from the reaction of two or more chemicals.
Food dye is not an industrial dye. A higher standard is maintained during processing. It is generally used as a food additive. Generally, direct dyes, vat dyes, and mordant dyes are used. Food dyes standards are also controlled hardly by the legislature.
Properties of Dyes:
- Firstly, dyes can be water-soluble or water-insoluble.
- Secondly, some dyes are anionic, some are cationic or some have both anionic and cationic properties.
- Thirdly, some dyes need low temperature and pressure to make a solution, some need high temperature and pressure to make a solution.
- Lastly, all of the properties of dyes depend on the molecular structure of dyes.
Molecular Structure of Dyes
Now, the dye molecule bears some group that is responsible for producing color. The chromophore group is responsible for color production.
The color-bearing unsaturated group of a dye molecule is called the Chromophore group. The following are some chromophore group names. They are-
We know about Chromogen. Basically, the compounds containing a chromophore are called Chromogen. We know that the leaves of the plant are green because it contains chromogen. Also, Auxochrome is a color helping group, it does not produce color itself but depends on the color of chromogen. The Auxochrome may be acidic either basic like OH or NH2, COOH, NR2, etc.
In sum, dyes are very sensitive to atmospheric conditions. So it needs to keep in a standard atmospheric condition. Significantly, different world-famous companies are trying to improve the properties of dyes. So by the research, we can get more efficient dyes for the next day.